Chuck wrench with automatic release



NOV. 25, 1952 l J, DRQEGE 2,618,995

CHUCK WRENCH WITH AUTOMATIC RELEASE Filed Sept. 15, 1951 INVENTOR. Hzzrty {ro Patented Nov. 25, l1952 CHUCK WRENCH WITH AUTOMATIC RELEASE Henry J. Droege, Pottstown, Pa.

Application September 13, 1951, Serial No. 246,405

2 Claims.

The present invention relates to chuck wrenches or keys and it relates more particularly to safety wrenches or adjusting tools for rotary lchucksv and the like.

An object of the present invention is to provide a new and improved safety wrench or adjusting tool or key for rotary chucks and the like. Another object of the present invention is to provide a wrench or tool or key for use in tightening and loosening a rotary chuck or the like which will automatically and positively disengage itself from the chuck upon completion of the adjusting operation (so as to prevent it from inadvertently being left in the chuck and thereby to constitute a serious hazard, as a centrifugallyhurled missile, when power is applied to the chuck), without being forcibly ejected, bodily, from the chuck.

Other objects and advantages of the present invention are apparent in the following detailed description, appended claims and accompanying drawings.

In power-operated rotary drills and the like, the drill is releasably held by a plurality of gripping jaws which can be moved either to extended releasing position or to retracted gripping position by manual rotation of a camming sleeve mounted on the chuck somewhat above the jaws. In order to assure rm gripping action, the sleeve is customarily provided with a downwardly directed circular rack gear at its lower edge, which is adapted to be engaged and rotated by the pinion of an adjusting tool or wrench or key which can be rotatably fitted within one of a number of radial holes formed in the body of the chuck intermediate the jaws and the sleeve. If the tool is left in position, through inadvertence, at the end of the tightening operation, it represents a serious safety hazard, since, when power is applied to the machine, the centrifugal force generated by the rapid rotation of the chuck will hurl the adjusting tool outward at great velocity to cause injury to anyone it strikes.

In recognition of this problem, various suggestions have heretofore been made for tools which are forcibly ejected frm the chuck, by outward radial spring-pressure exerted thereon, as soon as the tool is released by the operator. This, too, has its disadvantages since the tool can easily be damaged or lost when thus forcibly thrown outward from the chuck.

Other suggested forms of safety adjusting tools have similarly had shortcomings in construction or mode of operation.

Accordingly, the present invention contemplates a new and improved adjusting tool or wrench or key which is of simple, inexpensive and strong construction; which has a positive and dependable disengaging action; which is less apt to be left in place at the end of the free of the chuck without being forcibly ejected therefrom.

In general, the novel safety chuck wrench of the present invention comprises a body or housing carrying a handle and having a pinion at one end for engagement with the gear rack of the chuck sleeve, and a pivot-pin axially movable relative to the body and normally springurged to retracted position in which its operating end is fully concealed within the body, the pivot-pin being movable to extended chuck-engaging position by finger-pressure exerted on a push-button provided on its opposite end, a release of said finger-pressure causing spring actuated retraction of the pivot-pin and automatic disengagement of the wrench from the chuck so that, if the operator lets go of the Wrench it will simply fall away from the chuck. 1

For the purpose of illustrating the invention, there is shown in the accompanying drawings one form thereof which has been found in practice to give satisfactory results and which is presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities disclosed.

Referring to the accompanying drawings in which like reference characters indicate like parts throughout, Fig. 1 is an elevational view of the safety wrench of the present invention as it appears in use in engagement with a chuck; and Fig. 2 is an enlarged cross-sectional view of the embodiment of Fig. 1 as it appears with its pivot-pin in retracted position. 1

The embodiment of Figs. 1 and 2 includes a one-piece body or housing I0 of metal or the like having a cylindrical, axially-extending bore Il at its forward end and an enlarged counterbore I2 extending rearwardly therefrom. A driving pinion I 3, having bevel gear teeth, is provided at the forward end of the body ID, in peripheral, radially-spaced relationship to the forward. end of the bore I I. A two-piece handle or grip I4 is press-Fitted or otherwise suitably secured within diametrically-opposed openings formed in an enlarged annular shoulder I5 of the bodyl I0.

A pivot-pin I6 is mounted within the body IU in axially-movable relationship thereto. IThe pivot-pin I5 includes a cylindrical forward por-` tion I1 adapted to slide freely within the bore II and extending rearwardly therefrom into the enlarged counterbore I2. The portion I1 of the pivot-pin terminates in an enlarged cylindrical stop-shoulder I8 disposed within the counterbore; the pivot-pin also including a cylindrical rear portion I9 extending rearwardly from the stop-shoulder I8 and beyond the rear end of the 3 body l0. A push-button is provided on the outer rear end of the portion I9.

The rear "end of vthe counterbore vI2 fis lclosed by a plug v2| vsuitably secured therewithin (as, for example, by press-fitting, soldering or the like) and provided with a cylindrical opening through which the rear portion I9 of the pivotpin extends in sliding relationship therewith.

Disposed within the counterbore I2 is a helical compression spring 22 which surrounds 'the portion I1 of the pivot-pin and has its front end seated against the annular front Wall 23 'of the counterbore and has its rear end bearing against the stop-shoulder i8, so as normally to urge the pivot-.pin it to the position shown kin Fig. 2, wherein the :for-ward `portion l 'i is .fully retracted and concealed `within .the body lo, the stop-shoulder beingheld against the plug 2l by .the pressureof the spring-22- However, when the v.pushbuttonf yis-movedforward by the thumb of the user las indicated in Fig. 1, the pivot-.pin i6 is shiftedforward, against .thepressureof the spring 22, soas to cause .the frontend of the forward portion il to protrude appreciably beyond the frontendcf the bore i i. When the thumb is removed from Athe push-button 2G, the pressure of the spring 22 immediately returns the pivot-pin l5 Vto its'original retracted position of Fig. 2.

In.l3ig. .1, the wrench of the present invention is shown in conjunction with a conventional chuck having Va .plurality of adjustable gripping jaws 24 contained within the lower end of the chuck-housing 25, with a camming sleeve 2G disposed somewhat above the lower open end 21 of the chuck-housing 25 and with a plurality of circumierentially distributed radial sockets 2S formed in the chuck-housing 25 intermediate the lower-end 2l andthe sleeve 26. A downwardly directed circular rack `gear v23 is formed on the lower vedge .of the sleeve 26, with bevel teeth capable of .meshing with the teeth of the driving pinion I3.

.In use, the wrench is held in the hand with the fingers gripping the handle lli and with the thumb pushing the thumb-piece or push-button 2i? to forward position, whereuponthe extended front end of the portion Il is inserted within one of the sockets 2B until the driving pinion i3 meshes with the'rack gear 2S as yshown in'Figl.

The wrench is then turned torotatethe'sleeve Z5 and thereby 'to cam the jaws into gripping ('or releasing) relationship'with the drill 3G orr other sul sible rotary tool. 'When the jaws Yhave been sufficiently 'tightened `(or loosened) the wrench 'is disengaged from the chuck by simply pulling it radially away therefrom.

However, should the operator forget to pull the tool free, and instead merely release it (intending to' dot'something else) removal of the thumb from the push-button 29 causes spring-'actuated retractionof the forward portion il of the pivot-v pin t6-in -the manner described above, so -that there fis no longer any engagement between the pivot-pin and the socket 28 and, since there is nothing to support it, the wrench 'falls more or less -straightdown and away from chuck. Since Y the work-supporting surface (not shown) of the drill-press or other tool is relatively close to the chuck., it Yis apparent that the wrench will fall only a -short'distance onto said surface, and the chances of damage to, .or loss of, the wrench are minimized.

4 The fact that the forward portion I1 of the pivot-pin is fully retracted within, and concealed and protected by, the 'bo'dy or housing of the wrench when not in use further reduces the chances of damage should the wrench be dropped I'or fall to the ground during the automatic releasing action described above.

The present invention may be embodied in other forms and, accordingly, the above-described embodiment is to be considered merely as illustrative, and not restrictive, reference being made to the appended claims, rather than to the foregoing description, as indicative of the scope of the invention.

.Having thus described my invention, I claim as new and desire to protect by Letters Patent:

`1. For use with a rotary `chuck having a body provided with a radial socket and havinggripping jaws` and having a jaw-actuating sleevesurrounding the body and provided witha peripheral bevel rack-gear in `proximity to -said socket; a `safety wrench Vfor rotating said sleeve to adjust said jaws, said wrench comprisingan elongated Ihousing having a generally cylindrical axial bore formed therein and having a handle for axial rotation thereof and having a rack-gear-engaging bevel pinion formed on its forward end peripherally 4of said bore, an elongated generally cylindrical pivot-pin slidably and rotatably mounted within the cylindrical axial bore of said housing with its rear endY protruding therefrom, land a spring operatively disposed within said bore and urging said pvot-pin to rearward position wherein the front end of the pivot-pin is fully re-i tracted within, and concealed by, the forward end of the housing, the protruding rear end of the pivot-pin being adapted'to be pushed forward 'by thumb-pressure to move the frontend thereof to extended position beyond -the housing `whereby said front end can be inserted within the socket of the chuck and serves to support the Wrench for rotational movement thereabout, the housing being rotated by means of its handle independently of the pivot-pin with the pinion engag-ing anddriving the rack-gear, release of the rear end of the 'pivot-pin by removal of thumb-pressure causing automatic spring-urged retraction of the pivot-pin disengaging it from the socket and permitting the wrench to fall free of the chuck. Y

2. A construction according to claim 1 wherein the housing has a cylindical vbore in its forward end and an'enlarged counterboreextending rearwardly therefrom and an vapertured plug closing the rear end of the counterbore, and wherein the forward end 'of the pivot-pin slides within the bore and extends into the counterbore and terminates in an enlarged stop-shoulder within the counterbore, and wherein the rear end of the pivot-pin extends through the apertured plug and is provided with a push-button at its free end, and wherein the spring is a helical compression spring disposed within the counterbore and bearing against the shop-shoulder.

HENRY J. DROEGE.

REFERENCES CETD The following references are 4of record in the file of this patent:

NITED STA''VES PATENTS Willette f June `l., 19218 

